I think it comes from the US already 'cut up' for ad breaks and C4 probably can't do anything about it. In the US they have even more breaks than we do here.
It makes you realise how much time is spent on ads in the US. It is sold as an hour long show but without the ads is probably just over 40mins an episode. Like 24 which was meant to be in real time but on the BBC each episode was 45 mins as there were no ads. I agree with the previous answer record and fast forward...